U.S. Pat. No. 7,750,637 discusses a transmission line that is especially provided for connecting an electrical device, like for example an accessory device of an MR imaging system, to a connection unit, like for example a power supply or a control unit. The transmission line is also suitable for connecting implants especially with long conductors or electrodes, like for example heart pacemakers or artificial nerves, for supplying power to preamplifiers, for MR compatible IVUS (intravascular ultrasound) devices, for tracking of catheters or guide wires during MR image generation, and other applications which require a transmission line which is safe when guided through an RF field (for example generated by an MR imaging system). The transmission line comprises at least one transformer for coupling at least two lead segments of the transmission line and for providing safety of the line when guided through an RF field, wherein the lead segments and/or the transformer are provided in the form of at least one metallic structure on a substrate. The transmission line finds use in electrophysiology catheters used in cardiac interventional procedures performed under MR guidance.